The present disclosure generally relates to diversion operations in the oil and gas industry and, more specifically, to methods and treatments with self-degradation swelling compositions for diversion operations in subterranean formations.
Treatment fluids can be used in a variety of subterranean operations. Such subterranean operations may include, without limitation, drilling operations, stimulation operations, production operations, remediation operations, sand control treatments, injection operations, and the like. As used herein, the terms “treat,” “treatment,” “treating,” and other grammatical variants thereof refer to any subterranean operation that uses a fluid in conjunction with achieving a desired function and/or for a desired purpose. Use of these terms does not imply any particular action by the treatment fluid or a component thereof unless expressly described as such herein. Illustrative treatment operations can include, for example, fracturing operations, gravel packing operations, acidizing treatments, scale dissolution and removal operations, consolidation operations, diversion operations, and the like.
When performing a subterranean treatment operation, it can sometimes be desirable to temporarily block or divert the flow of a fluid within at least a portion of the subterranean formation by forming a fluid seal therein (e.g., to direct the operation to a particular portion of the subterranean formation). The formation of a diverting fluid seal can itself be considered a treatment operation. Illustrative fluid blocking and diversion operations can include, without limitation, fluid loss control operations, kill operations, conformance control operations, and the like. The fluid that is being blocked or diverted can be a formation fluid that is natively present in the subterranean formation, such as petroleum, gas, or water, or a type of treatment fluid, such as those mentioned above.
Providing effective fluid loss control during subterranean treatment operations can be highly desirable. The term “fluid loss,” as used herein, refers to the undesired migration or loss of fluids into a subterranean formation (e.g., from a wellbore penetrating the subterranean formation) and/or a particulate pack (e.g., a particulate pack in a fracture). Fluid loss can be problematic in a number of subterranean operations including, for example, drilling operations, fracturing operations, acidizing operations, gravel-packing operations, workover operations, chemical treatment operations, wellbore clean-out operations, and the like. In fracturing operations, for example, fluid loss into the formation matrix can sometimes result in incomplete fracture propagation and added expense. Formation of a fluid seal in such treatment operations can mitigate the fluid loss.
Likewise, in the reverse of a fluid loss event, incomplete fluid blocking can result in production of an unwanted fluid from a portion of a subterranean formation. For example, incomplete formation of a fluid seal may result in the unwanted incursion of formation water or brine into a wellbore, which may add additional expense and complexity to recovering and purifying the hydrocarbon resources produced therefrom.
Removal of a blocking or diverting substance from a subterranean formation after use may also be desirable once the requisite fluid diversion has been accomplished, for example, to improve the success rate of completion operations, reduce the frequency of necessary remedial operations, reduce formation damage that may impair production rates, reduce problems associated with setting and retrieving downhole tools, reduce operational costs associated with these activities, and the like. Additionally, such removal may be desirable at time periods shortly after the diverting substance has been introduced into a subterranean formation and formed the diverter plug, thereby further reducing operational costs. As used herein, the term “diverter plug” (which may also be referred to as “sealant”) refers to a substance that inhibits the flow of a fluid between two locations (e.g., between portions of the wellbore, between two portions of a subterranean formation, between a portion of a wellbore and a portion of a subterranean formation, or between a portion of the wellbore and a portion of the tubular string disposed therein).